Help identify 70's era table lamp - George Kovacs?  

I'm trying to obtain custom 'original' shades to a lovely pair of table lamps I inherited. My father-in-law purchased them in the 1970's and believes they were by George Kovacs. Can anyone identify?

The lamps are heavy matte black metal with square base and sloped sides like a candlestick and have a textured finish. Dimensions of base are: 6" square (bottom), 3.5" square (top), and 17.25" tall (not including socket and harp.

For a visual, I made a 3D model and posted on SketchUp's 3D Warehouse under "Can you identify my retro table lamp?"
Thanks for any leads!